Jim Brown pauses during his singsong sales pitch at Whole Foods in Venice just long enough to replenish samples of his namesake tomato-based hamburger relish.

"You've got to use more cream cheese than cracker so you can take the relish to almost overflowing," he explains, swiping the bottom of a wheat cracker with a layer of cream cheese. He turns the cheese spreader upright, and then carefully builds a half-inch white wall on adjacent sides of the cracker to form a two-sided repository for the tangy condiment. "But it's really all about hooking and reeling [the customer] in."

For Brown, a 55-year-old Aliso Viejo stay-at-home dad and part-time personal assistant, the road from condiment-stained elementary school T-shirts to realizing his full relish potential has spanned nearly 50 years. And not because of the relish, really more of a ketchup-like sauce spiked with cider vinegar and diced vegetables. That practically came with a built-in local fan base.

For Brown, embracing his penchant for direct customer sales has been the challenge — and ultimately, the greatest reward.

"Have you tried my famous, award-winning relish?" Brown asks a potential customer before running through a litany of possible condiment-friendly foods, including burgers and roasted vegetables.

Today, he's most at home when pitching his pickled product. But the sales aspect of the job hasn't always been easy for Brown, who says he used to prefer hiding beneath his baseball cap. "For a lifelong introvert, this business has forced me to come out of my shell."

The relish is something Brown has always been comfortable with. He grew up slathering the stuff on hamburgers at the Rite Spot, the legendary Pasadena diner where short-order cook Lionel Sternberger claimed he invented the cheeseburger in the early 1920s. That first slice of American cheese may have brought the local hangout national fame, but it was the relish served in generous bowls that regulars like Brown remember most.

"I'd go there almost every day with my father," says Brown, slowly stirring a just-opened jar to make sure the finely diced onions, cabbage, cauliflower, bell peppers and celery wind up on each cracker. "There was something different about that relish's flavor."

Sternberger eventually sold the Rite Spot and opened Sternberger's diner in Highland Park with his brother, Van. When Sternberger's closed in 1967, the relish recipe disappeared along with it.

But Brown and his father, Harry, were not ready to relinquish their dreams of pickled vegetable grandeur. In 1979, Harry contacted the former general manager of Sternberger's diner, Ernie Riedel, and persuaded him to reveal the recipe. After converting two former drive-throughs (one in Orange, one in Santa Ana), father and son were in the diner business using a familiar alias: Jim's Rite Spot.

Only flipping burgers all day wasn't as easy as Brown had envisioned. "I had no idea what I was getting into," Brown says. They struggled to keep the diners afloat, eventually closing both in 1981.

"I had no desire to be in the food business ever again," he says. But when his father died, Brown changed his mind. "I decided I was the last person on Earth who knew how to make this relish."

He tinkered with the original recipe with the help of Barry Weinstein, a Fullerton-based food scientist. Some tweaks came down to personal taste, such as increasing the amount of cloves for a spicier kick. Others, like thickening the relish's soupy consistency, were necessary for commercial production. "You need a more concentrated product when you go from table to bottle so it goes further when a customer buys it," Brown explains.

In late 2006, he took the final step by turning to jam and jelly maker E. Waldo Ward in Sierra Madre to manufacture his product. Now the trick was figuring out how to market a new relish based on an old favorite that many grocery store shoppers might not remember.

"I see a lot of little guys like Jim who have a great product, but they don't have any idea how to sell it," says Bob Bacca, owner of El Toro Gourmet Meats in Lake Forest. Bacca, the first retailer to stock Jim Brown's Relish, says Brown wasn't always as adept at that hook-and-reel sales technique as he is today.

At his first customer demo at El Toro three years ago, Brown handed out the hamburger relish in a paper condiment cup. Bacca suggested he serve it on a cream cheese-topped cracker (it would taste better), and that Brown play up uses other than burgers so customers might buy it more often.

"I really had no idea what I was doing then, but I guess I have that sales gene in me somewhere," says Brown, pausing momentarily from his cream cheese well construction. In 1903, his grandfather, Curtis Beauchamp, founded Western Dental, today the largest provider of dental services in California. "That was largely a sales job."

Still, Brown had his own floor act to perfect. "People say they sing in the shower. I pitch the relish to myself."

Today, Brown has that pitch down to an art. With his relish in more than four dozen Whole Foods in Southern California and surrounding states, he could cut back on the sales runs — if he didn't enjoy them so much.

"Do you do infomercials?" a Venice shopper asks. She grins and carefully picks up a cracker, trying not to spill the mound of relish onto her white tennis skirt. Brown uses the opportunity to list the dozen items he likes to serve with the relish, including hot dogs, hamburgers, steak, eggs, tuna salad, grilled seafood, even pizza — all rather impressively revealed in one breath.

The pizza idea came from his 6-year-old son, James "Jamie" Brown II, who has yet to taste the relish.

"He's a picky eater," his father says. "But he's seen me do the demos, and he can't wait until he's old enough to do them himself."

Jim Brown's Relish is available at El Toro Gourmet Meats in Lake Forest, Marbella Market in San Juan Capistrano and most Southern California Whole Foods stores for about $4 a jar.